Area Forecast Discussion
Issued by NWS Wilmington, NC

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000
FXUS62 KILM 040926
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
426 AM EST WED MAR 4 2015

.SYNOPSIS...
A WARM FRONT WILL LIFT NORTHWARD ACROSS THE CAROLINAS THIS
MORNING...ALLOWING SOUTHWEST WINDS TO SCOUR OUT THE COLD AIR.
TEMPERATURES WILL RISE INTO THE 70S TODAY AWAY FROM THE
IMMEDIATE COAST. A COLD FRONT WILL MOVE THROUGH THURSDAY AFTERNOON
WITH SHARPLY COLDER AIR INVADING THE REGION THURSDAY NIGHT AND
FRIDAY...LINGERING INTO SATURDAY. TEMPERATURES WILL GRADUALLY WARM
EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM WEDNESDAY...EVEN WITHOUT A HIGH TO HOLD IT IN PLACE...THE
WARM FRONT HAS HAD ITS NORTHWARD PROGRESS THWARTED BY THE PONDEROUS
WEIGHT OF THE SHALLOW COLD AIRMASS STILL CLINGING TO THE SURFACE.
JUST 1500 FEET UP SOUTH WINDS ARE INCREASING BEYOND 30 KNOTS AND MAY
APPROACH 40 KNOTS AROUND SUNRISE. SUBTROPICAL MOISTURE ADVECTING
OVER THE COLD GROUND (AND ADJACENT OCEAN) HAS LED TO DENSE FOG. THIS
FOG SHOULD MIX OUT BY LATE MORNING AWAY FROM THE BEACHES.

AS SKIES BECOME PARTLY SUNNY A REMARKABLE CHANGE WILL OCCUR AS
TEMPERATURES SOAR TO 75-80 DEGREES INLAND. THAT`S NO JOKE!
TEMPERATURES WILL BE SIGNIFICANTLY COOLER ANYWHERE NEAR THE BEACHES
AS WINDS BLOW ONSHORE ACROSS 45-50 DEGREE WATER. THE WORST WEATHER
SHOULD OCCUR ALONG SOUTH-FACING BEACHES WHERE TEMPERATURES WILL
BARELY REACH 60 DEGREES WITH DENSE FOG CONTINUING THROUGH MOST OF
THE DAY. FOR THIS REASON I HAVE EXTENDED THE DENSE FOG ADVISORY FOR
THE BEACHES INTO TONIGHT DUE TO FAVORABLY ALIGNED WIND DIRECTIONS
AND CONTINUED HIGH DEWPOINTS RELATIVE TO OCEAN WATER TEMPERATURES.

RADAR SHOWS SHOWERS JUST SOUTH OF FLORENCE MOVING QUICKLY
NORTHEASTWARD. FORECAST SOUNDINGS INDICATE THE POTENTIAL FOR A FEW
MORE ELEVATED CONVECTIVE SHOWERS ESPECIALLY ACROSS SE NORTH CAROLINA
LATER TODAY...BUT COVERAGE SHOULD REMAIN ISOLATED.

FOR TONIGHT CONTINUED SOUTH-SOUTHWEST WINDS WILL HELP KEEP THE
BOUNDARY LAYER MIXED. RADIATIONAL COOLING SHOULD RESULT IN LOW
STRATUS DEVELOPING DURING THE EVENING HOURS...WITH A NEAR-SOLID
OVERCAST POSSIBLE AFTER MIDNIGHT EVEN INLAND. THIS WILL STABILIZE
TEMPERATURES IN THE LOWER 60S FOR MOST AREAS AWAY FROM THE BEACHES.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 400 AM WEDNESDAY...BROAD POSITIVELY TILTED UPPER TROF WILL
RULE THE EASTERN 1/2 TO 2/3RDS OF THE UNITED STATES. SPLIT FLOW
WILL CONTINUE ALOFT...WITH UPPER FLOW FROM THE SW TO START THE
SHORT TERM PERIOD...WHICH STARTS AT THU DAYBREAK. THIS WILL
PROVIDE SOME GULF OF MEXICO MOISTURE AND EVEN PACIFIC MOISTURE
PROVIDED IT DOES NOT SCOUR OUT WHEN CROSSING THE SOUTHERN ROCKY
MOUNTAINS. NEVERTHELESS...THIS FLOW WILL RESULT IN SLIGHTLY HIER
THAN NORMAL MAX TEMPS THU ALONG WITH PARTLY OR VARIABLY CLOUDY
SKIES. THE NORTHERN STREAM...DROPPING ACROSS THE U.S. FROM
CANADA...WILL BE PUSHING A SFC COLD/ARCTIC FRONT SOUTHEASTWARD.
AT THE START OF THE SHORT TERM PERIOD...THIS NORTHEAST TO
SOUTHWEST ORIENTED COLD/ARCTIC FRONT...WILL BE ON THE DOORSTEPS
OF THE ILM CWA. THE MAIN SWATH OF PCPN WILL OCCUR AFTER THE CFP
STARTING LATE MORNING THU...AND CONTINUING THU NITE BEFORE ENDING
MIDDAY FRI AS THE FRONT PUSHES FURTHER OFFSHORE.

NO DRAMATIC SFC LOW DEVELOPMENT ALONG THIS FRONT...AND THUS WILL
ACTUALLY RELY ON OVERRUNNING BEHIND THE FRONT AS THE VERY SHALLOW
ARCTIC AIR MASS PUSHES UNDER THE MILD/WARM AIR ALOFT. TEMPS AFTER
FROPA WILL DROP DRAMATICALLY COME LATE THU THRU THU NIGHT BEFORE
LEVELING OFF SOMEWHAT DURING FRI. THERE COULD BE A PERIOD OR ROUND
OF MIXED WINTRY PCPN DURING THE PRE-DAWN FRI HOURS...MAINLY NORTH
OF HIGHWAYS 74-76 WITHIN THE ILM CWA. THE COLD AIR DEPTH AT THE
LOWER LEVELS WILL BE A DETERMINING FACTOR OF WHETHER IP WILL BE
INTRODUCED INTO THE PCPN...AND ALSO THE SFC TEMP ITSELF. SREF
INDICATES A CHANCE FOR SLEET ALONG WITH FREEZING RAIN FOR A
PORTION OF THE ILM CWA. WITH A GOOD 2-3 DAYS OF SFC TEMPS WELL
ABOVE FREEZING...WILL HOLD OFF WITH THE MENTIONING OF LIGHT
FREEZING RAIN OR DRIZZLE MIXING IN...LET ALONE ANY ACCRETION. IF
ANYTHING...A TRACE OF IP MAY OCCUR BEFORE MELTING COME FRIDAY
DAYBREAK.

AS FOR FRI MAX TEMPS AND SAT MORNING MINS...STAYED CLOSE TO THE
HIER SIDE OF MOS GUIDANCE IE. THE NAM MOS GUIDANCE. 850MB PROGGED
TEMPS BARELY BREAK 0 DEGREES DURING FRIDAY...AND EVEN STAY ABOVE 0
DEGREES FOR MUCH OF FRI NITE. THIS ILLUSTRATING HOW SHALLOW IN
DEPTH THIS SFC BASED ARCTIC AIRMASS IS TO BECOME. EVEN PROGGED
925 MB TEMPS...ALSO HOVER AROUND 0 DEGREES FRI NITE. THE AREA MAY
BE SUBJECT TO SOME RADIATIONAL COOLING LATE FRI NITE AS SKIES
CLEAR OUT AND THE SFC PG RELAXES...ALONG WITH SFC DEWPOINTS
RANGING FROM THE TEENS IN THE NORTH TO 20S SOUTH.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 3 PM TUESDAY...THE MID LEVEL PATTERN WILL CONTINUE TO
DOMINATED BY A BROAD TROUGH TROUGH MOST OF THE PERIOD WITH SOME
SIGNS OF RELAXING BY THE MIDDLE PART OF NEXT WEEK. INITIALLY THE
TROUGH USHERS IN YET ANOTHER ARCTIC AIRMASS THAT WILL BE IN PLACE
FRIDAY AND SATURDAY. TEMPERATURES WILL BE WELL BELOW NORMAL WITH
HIGHS IN THE 40S FRIDAY AND LOWS IN THE MIDDLE 20S SATURDAY.

ANOTHER SHORTWAVE EMERGING FROM THE GULF OF MEXICO RIDES ALONG THE
OLD FRONT OFFSHORE SATURDAY WARRANTING LOW CHANCE POPS FOR SATURDAY
THROUGH SUNDAY MORNING WITH THE HIGHEST CHANCES ALONG THE COAST.
MARCH SUNSHINE WONT HAVE MUCH OF A CHANCE TO WARM THINGS UP WITH
HIGHS ONLY THE 50S BUT THE MOISTURE WILL LIMIT LOWS TO THE MIDDLE
30S. LETHARGIC WARMUP CONTINUES SUNDAY THROUGH TUESDAY UNDER PARTLY
SUNNY SKIES AS WEAK HIGH PRESSURE RESIDES AT THE SURFACE. MEDIUM
RANGE GUIDANCE IS SHOWING ANOTHER SYSTEM FOR THE MIDDLE PART OF NEXT
WEEK WITH THE ECMWF THE FASTER SOLUTION. WILL KEEP THE FORECAST DRY
FOR NOW.

&&

.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
AS OF 06Z...VERY LOW STRATUS AND AREAS OF DENSE FOG EXIST AHEAD OF A
WARM FRONT APPROACHING FROM THE SOUTH. THIS FRONT WILL BE VERY SLOW
TO TRANSIT THE EASTERN CAROLINAS...LIKELY TAKING SEVERAL HOURS AFTER
DAYBREAK TO LIFT PAST THE ILM AND LBT AIRPORTS. BEHIND THE FRONT
VSBYS WILL PROBABLY IMPROVE AT THE LBT/FLO/ILM AIRPORTS...HOWEVER
CRE/MYR MAY REMAIN IN THE SOUP AS DENSE SEA FOG GENERATED BY THE
INTERACTION OF SUBTROPICAL MOISTURE WITH VERY COLD NEARSHORE OCEAN
SURFACE TEMPERATURES CONTINUE.

ACCELERATING SOUTH WINDS JUST ABOVE THE SURFACE WILL NOT MIX DOWN
EFFECTIVELY TO THE GROUND UNTIL LATE MORNING TO AROUND NOON. UNTIL
THEN THIS WILL CREATE HAZARDOUS WIND SHEAR CONDITIONS AS 1000 FOOT
WIND SPEEDS INCREASE TO 30-40 KNOTS.

EXTENDED OUTLOOK...SHOWERS WEDNESDAY NIGHT...BECOMING IFR WITH LIGHT
RAIN AND FALLING TEMPERATURES ON THURSDAY. IFR CONDITIONS MAY LINGER
ALONG THE COAST ON FRIDAY. VFR SATURDAY THROUGH MONDAY.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM WEDNESDAY...A WARM FRONT IS CRAWLING NORTHWARD ACROSS THE
WATERS AND SHOULD FINALLY LEAP NORTH OF THE AREA LATER THIS MORNING.
SUBTROPICAL MOISTURE SURGING NORTHWARD ACROSS THE VERY CHILLY WATER
TEMPERATURES IS RESULTING IN DENSE FOG. WITH SOUTH-SOUTHWEST WINDS
CONTINUING THROUGH TONIGHT I SEE NO REASON WHY THE FOG WILL
END...AND I AM INCLUDING WIDESPREAD DENSE FOG IN THE FORECAST
THROUGH TONIGHT. WIND SPEEDS SHOULD INCREASE TO AROUND 15 KNOTS BY
LATE MORNING...REMAINING THERE THROUGH TONIGHT.

STRONGER WINDS JUST 30-60 OFFSHORE WILL GENERATE A 6-7 SECOND SWELL
THAT WILL PROPAGATE WESTWARD INTO THE COASTAL WATERS...PUSHING TOTAL
SEA HEIGHTS UP TO 3-5 FEET. THIS SWELL SHOULD EXCEED ANY LOCALLY
GENERATED WIND WAVES AND REMAIN THE DOMINANT WAVE SET.

SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
AS OF 3 PM TUESDAY...MARINE CONDITIONS WILL BECOME INCREASINGLY
UNFRIENDLY WEDNESDAY INTO THURSDAY ASSOCIATED WITH AN APPROACHING
COLD FRONT...BUT AN ADVISORY MAY NOT BE NEEDED UNTIL THURSDAY...AS
THE WARM AIR MAY STRUGGLE REACHING THE COLD DENSE AIR ABOVE THE
CHILLY SSTS IN PLACE. IF NOT ADVISORY CONDITIONS PRIOR TO THE
FRONTAL PASSAGE THEN CERTAINLY BEHIND IT...AS VERY COLD AIR
SPILLS OVER THE WATERS...WITH AT A MINIMUM 30 KT GUSTS EXPECTED
LATE INTO THURSDAY NIGHT. THE OTHER HAZARD PRIOR TO FRONTAL
PASSAGE IS THE LIKELIHOOD OF SEA FOG AS BALMY AIR TRACKS OVER THE
FRIGID WATERS...REDUCING VSBYS AT TIMES. RAIN THURSDAY AFTERNOON
AND NIGHT MAY ALSO RESTRICT LINE OF SIGHT.

LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 3 PM TUESDAY...BRISK NORTHERLY WINDS ON THE ORDER OF 20-25
KNOTS WILL PREVAIL ACROSS THE WATERS INITIALLY AND MOST OF FRIDAY AS
ARCTIC HIGH PRESSURE BUILDS IN. AS WE HAVE SEEN MANY TIMES THIS
SEASON THE WINDS GRADUALLY DIMINISH AS THE HIGH MOVES IN WITH SPEEDS
DROPPING TO AROUND TEN KNOTS BY MIDDAY SATURDAY. FOR THE REMAINDER
OF THE PERIOD WINDS WILL BE WEAKLY FORCED AS A WEAK PRESSURE PATTERN
DEVELOPS. IF ANYTHING WINDS MAINTAIN A NORTHERLY COMPONENT AS A WEAK
SHORTWAVE PASSES ALOFT WITH NEGLIGIBLE SURFACE FEATURES. SIGNIFICANT
SEAS YIELD NO SURPRISES WITH SOME HIGHER VALUES FRIDAY...MOSTLY
CONFINED TO THE OUTER WATERS. BY LATER SATURDAY VALUES DROP TO 1-3
FEET.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR SCZ017-023-
     024-032-033-039-053-055.

     DENSE FOG ADVISORY UNTIL 6 AM EST THURSDAY FOR SCZ054-056.

NC...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR NCZ087-096-
     099-105-107-109.

     DENSE FOG ADVISORY UNTIL 6 AM EST THURSDAY FOR NCZ106-108-110.

MARINE...DENSE FOG ADVISORY UNTIL 6 AM EST THURSDAY FOR AMZ250-252-254-
     256.

&&

$$
SYNOPSIS...DCH
NEAR TERM...TRA
SHORT TERM...DCH
LONG TERM...DCH
AVIATION...TRA






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